In the Happiest Baby video, the swining/jiggling is demonstrated and then showed how to use the swing to continue the motion after the baby has calmed down. Do baby bouncers (that vibrate) work as well as swings?

Vibrating chairs do work for some, although Dr. Karp recommends using swings instead of vibrating chairs as the swing will work much better. Please make sure you have watched The Happiest Baby DVD a few times as it is extremely important to implement the techniques correctly (swaddled snuggly, safely strapped into the seat, background CD of white noise, etc).